Engine supply system



Patented Aug. 13, 1935 UNITED PATENT, OFFICE} 14 Claims. (01. 123-119) This invention relates to engine supply systems, and more particularly to an engine supply system wherein superchargers of different characteristics are used.

Superchargers for internal combustion. engines are ordinarily of either the positive type or of the centrifugal type, both of which have inherent objectionable characteristics.- .The centrifugal type delivers large volumes and pressures at its rated speed and is more compact" and lighter than the positive type, but will not. deliver suflicient pressure at starting or idling speeds. The positive type delivers its full pressure at low speeds, but mechanical limitations make it impractical for operation at very high speeds; henc it is larger and heavier than the centrifugal type designed for some specific deliveryconditions.

, An object of the present invention is to provide an engine supply system wherein both types are used and in which one supercharger, preferably .the positive type, is automatically disengaged before high speed is attained.

Another object of the invention is to provide an engine supply system having a, supercharger arrangement wherein the low speed air supply is obtained from a positive type supercharger and the high speed air supply from a centrifugal type supercharger.

Another object of the invention is to provide an engine supply system wherein a pair of superchargers of difierent discharge characteristics idnay efficiently supply a common discharge con- Another object of the invention is to provide an engine supply system wherein two superchargers may be employed without danger of diverting the air charge from the engine, irrespective of the driving connection of either supercharger.

Other objects of the invention will appear from the following description, in connection with which certain embodiments have been illustrated in the accompanying drawing,.in which:

Fig. l is a somewhat diagrammatic view. illustrating the improved arrangement of the interconnected superchargers;

Fig. 2 is an enlarged view partly in section of the inter-connecting clutch;

Fig. 3 is an enlarged sectional view taken on the line 3--3 of Fig. 2; and,

Fig. 4 is a diagrammatic view illustrating a somewhat different embodiment of the invention.

In the drawing, with particular reference to Fig. 1, I8 is a carburetor adapted to have its discharge opening II connected to an engine, not shown, and its inlet pipe 12 connected to the discharge opening of a positive type supercharger I3 which, in the illustrative embodiment, is of the sliding vane type and includes a housing l4 and an engine driven rotor 16 mounted eccentrlcally in the housing l4 and provided with a plurality of sliding vanes l1. Rotor shaft I8 is mounted in supports I9 by any desired means, such as bearings 2|, and has its driving end connee-ted with the engine driven shaft 22 by a cured to shaft 18 by any desired means, such as set screw 36, and a. driving disc 42 preferably slidably secured to shaft 22. A plurality of radially slidable centrifugal weights 31 are secured 'to spider 34 by stems 38, about which are springs 39 for urging them to their outer position. The inner ends of stems 38 are provided with stops 4| for limiting outward movement of weights 31 and preventing them from moving outwardly beyond a predetermined point. Disc 42 is prefer-. ably slidably mounted on shaft 22 by splines 43 and has a conical face 44 adapted to frictionally contact with the weights 31. An annular ring member 46 having a conical face 41 adapted to engage the opposite side of weights 31, is slidably mounted with respect to disc 42 by means of a plurality of pins 48that are fixedly secured to disc 42 by threaded stems 49 and lock nuts 51. Annular friction member 46 is normally urged toward disc .42 by springs 53 that coact between the heads 54 of pins 48 and the outer surface of ring 46. Pins 48 are each provided with a groove 56 within which is a lock pin 51 axially slidable in opening and normally held in the groove by a spring 59 coacting against flange BI and the inner face of threaded plug 62.

In the'low speed operation of the device, the impeller 21 of the centrifugal supercharger and the rotor l6 of the positive supercharger are both driven from the engine, for under low speed conditions, the centrifugal clutch 23 is in the posi- Inlet passage 24 of the positive type tion illustrated in Fig. 3 and the opposed conical faces 41 and 41 are in frictional engagement with the wedge-shaped weights 31. If the speed of shaft 22 be increased beyond a predetermined point, the outward pressure of weights 3'! is increased by centrifugal force and the inward pressure of springs 59 is reduced by the centrifugal force of pins 51, so that at the predetermined point, pins 51 move outwardly from the notches 56 and release the annular ring 46, whereapon it will be moved axially to its inoperative position by the outward force of weights 31. Disc 42 may also slide upon shaft 22 and be disengaged from the surface of weights 31, which have their outward movement limited by stops 4 l If the speed of shaft 22 be decreased, the inward force of springs 59 is increased and pins 51 will have a. tendency to move along the conical portions of pins 48 to again engage the grooves 56, which movement will be assisted by theaction of springs 53. If desired,- springs 53 may be eliminated and the inwardmovement produced by the selection of springs 59 of suitable strength.

In the engaged position of the clutch which preferably occurs during low speed operation, very little pressure is produced by the centrifugal supercharger and the engine is supplied principally by the positive type. After the predetermined speed has been reached, the centrifugal supercharger is able to produce the necessary pressure, and disengagement of the clutch permits the positive type supercharger to rotate idly and allow the air to pass therethrough on its way to the engine. I

In the form of the invention shown in Fig. 4, the centrifugal and positive superchargers are arranged in parallel, whereby the inlet H of the positive supercharger and inlet 12 of the centrifugal supercharger each takes its supply of air from the atmosphere and delivers it through outlet conduits 13 and 14 respectively, to a-common discharge outlet 16. In this form 'of the invention, outlet conduits I4 and 13 are each provided "with check valves TI and 18 respectively, which prevent either of the. superchargers from discharging through the 'other when the delivery pressure of either is reduced below that of the other.

It may be readily seen from theabove description that an engine supply system has been provided in which both a positive and a centrifugal type of supercharger are connected to a common outlet, and the positive supercharger adapted to be automatically disconnected from the driving means at a point whereat the centrifugal supercharger develops suflicient pressure for delivery to the engine. It also may be seen that, as the positive supercharger is automaticalstood that this showing and description are illustrative only and that the invention is not regarded as limited to the embodiments illustrated and de-- ly disconnected, it may be made of small size, for

there is no danger of seizure from excessive speed, and that it may be driven at sufficient speed to deliver a large quantity of air at comparatively low engine speeds. a

While certain embodiments of the invention have been illustrated and described, it is underscribed, or otherwise, except bythe terms of the following claims. v

What is claimed is: 1. In an engine supply system, a positive type supercharger, a centrifugal type supercharger, driving means therefor, and a centrifugal clutch a common outlet for the superchargers, a cen-' trifugally actuated device for disconnecting one supercharger at high speed, and spring means for reconnecting the same when the speed is reduced to a predetermined point.

3. In an engine supply system, a pair of superchargers having a common outlet and a common driving shaft, said shaft having aligned portions interconnected by a oentrifugally actuated clutch for disconnecting one supercharger at a predetermined speed;

4. In an engine supply system, a positive and a centrifugal type supercharger having a common outlet and a common driving shaft, said shaft having aligned portions interconnected by a centrifugally actuated clutch for disconnecting the positive type supercharger at a predetermined speed.

'5. In an engine supply system, a pair of superchargers having their discharge passages connected in series, driving means therefor, and means automatically operative at a predetermined speed of the supercharger for disconnecting the driving means of one supercharger from the main driving means.

6. In an engine supply system, a positive and a centrifugal type supercharger having their discharge passages connected in series, driving means therefor, and meansoperative at a prev driving means at a predetermined speed.

8. In an engine supply system, a positive and a centrifugal type supercharger, driving means therefor, said centrifugal type supercharger having its outlet connected to-the inlet of the positive type supercharger, and a oentrifugally actuated clutch for disconnecting the positive type supercharger from the driving means at a predetermined speed.

9. In an engine supply system, a'positive and a centrifugal type supercharger, driving means therefor, said superchargers having separate inlets and a common outlet, and a oentrifugally actuated clutch for disconnecting the positive type supercharger at a predetermined speed.

10. In an engine supply system, a positive and a centrifugal type supercharger,. driving means therefor, sa'id superchargers having separate inlets and a common outlet, means for operatively disconnecting the positive type supercharger from the driving means at a predetermined speed, and means for preventing. each supercharger from discharging through the other.

11. In an engine supply system, a pair of engine drigen superchargers having a common outlet, means responsive to supercharger speed for operatively disconnecting one supercharger at a predetermined speed, said means including a latch device providing a quick release for the supercharger.

12. In an engine supply system, a pair of engine driven superchargers having a common outlet, means responsive to supercharger speed for operatively disconnecting one supercharger at a predetermined speed, said means including a clutch having a member axially movable by eentrifugal force to disengage the same, and a latch radially movable by centrifugal forceadapted to chargers and said centrifugal supercharger arranged to discharge through the positive supercharger.

14. In an engine supply system, a of superchargers having difierent discharge characteristics, a common outlet for both supercharge a. common driving shaft therefor said shaft being divided into two portions intermediate the superchargers, and a speed responsive clutch connecting the portions adapted to disconnect the 10 shaft portions at a predetermined speed.

- DAVID GREGG. 

